Build
A unique aspect of the Android system design is that any app can start another app’s component.
Android Developers Fundamentals
Try to avoid "Hello JMB!":
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
...
<TextView android:text="Hello JMB!" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
Use "@string/message" instead:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
...
<TextView android:text="@string/message" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout><resources>
<string name="app_name">My First App</string>
<string name="action_settings">Settings</string>
<string name="message">Hello JMB!</string>
</resources>content_main.xml is a kind of Layout.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
...
<TextView android:text="@string/message" android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>A Layout contains components (buttons, etc.) ⇒ Views
Activities communicate through Intent.
In the same app:
Or between apps:
| AVD: Android Virtual Device |
Check the Android fundamentals, enrich the list of important concepts and organize them.
Activities
Manifest.xmlThis web site has been developped by JMB using the following (open and free) tools:
1.5.5